linux-kernel - Re: [PATCH v3] virtio: Add platform bus driver for memory mapped virtio device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87ty75adtb.fsf@rustcorp.com.au>
Date:	Wed, 19 Oct 2011 13:27:20 +1030
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	Pawel Moll <pawel.moll@....com>
Cc:	"linux-kernel\@vger.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel\@lists.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"virtualization\@lists.linux-foundation.org" 
	<virtualization@...ts.linux-foundation.org>,
	Anthony Liguori <aliguori@...ibm.com>,
	"Michael S.Tsirkin" <mst@...hat.com>
Subject: Re: [PATCH v3] virtio: Add platform bus driver for memory mapped virtio device

On Tue, 18 Oct 2011 10:44:35 +0100, Pawel Moll <pawel.moll@....com> wrote:
> > or actually specify it as
> > the power of 2 to use, (ie. valid values are 1 through 16, with 12 being
> > the value that virtio PCI would use).
> > 
> > Otherwise you have to do a divide on the qemu side.
> 
> Oh, really? My host-side implementation is just doing that:
> 
>         addr += align - 1;
>         addr &= ~(align - 1);

OK, so you're assuming power of 2.  Make sure you kill the guest or at
least the device if it's not though.

> \item The dynamic configuration changes, as described in p. 2.4.3
> ``Dealing With Configuration Changes'' are not permitted.

This means some devices simply won't work, at least in theory.  Why
don't you support this?

Thanks!
Rusty.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/